2 5-benzodiazonin-3-ones

ABSTRACT

THIS INVENTION RELATES TO NITROGENEOUS HETEROCYLIC COMPOUNDS WHICH ARE USEFUL AS ANTI-DEPRESSANTS. THE COMPOUNDS ARE OF THREE CLASSES, I.E. (A) 4-LOWERALKYL-2-OXO1,2,3,5,6,10B-HEXAHYDROIMIDAZO(2,1-A)ISOQUINOLINIUM HALIDES, E.G. 8,9-DIMETHOXY-4-METHYL-1,2,3,5,6,10B-HEXAHYDROIMIDAZO)2,1-A)ISOQUINOLINIUM IODIDE; (B) 5-LOWERALKYL-2,5-BENZODIAZONIN-3-ONES, E.G. 9,10-DIMETHOXY-5METHYL-2,5-BENXODIAZONIN-3-ONE; AND (C) 5-LOWERALKYL2,5-DIAZONINES, E.G. 9,10-DIMETHOXY-5-METHYL-2,5-BENZODIAZONINE BIMALEATE. COMPOUNDS (A) MAY BE OBTAINED BY TREATING A 1,2,3,5,6,10B-HEXAHYDROIMIDAZO(2,1-A)ISOQUINOLIN-2-ONE WITH A LOWER ALKYL HALIDE, E.G. METHYL IODIDE. COMPOUNDS (B) MAY BE OBTAINED BY REDUCING COMPOUNDS (A) WITH SODIUM IN LIQUID AMMONIA. COMPOUNDS (C) MAY BE OBTAINED BY REDUCING COMPOUNDS (B) WITH LITHIUM ALUMINUM HYDRIDE.

United States Patent Office 3,655,648 2,5-BENZODIAZONIN-3-0NES William J. Houlihan and Robert E. Manning, Mountain Lakes, N.J., assignors to Sandoz-Wauder, Inc., Hanover, NJ.

No Drawing. Original application Mar. 17, 1967, Ser. No. 623,850, now Patent No. 3,551,411, dated Dec. 29, 1970. Divided and this application July 7, 1970, Ser. No. 52,991

Int. Cl. C07d 53/00, 57/04 U.S. Cl. 260-2393 B -2'Claims ABSTRACT OF THE DISCLOSURE This application is a division of application Ser. No. 623,850, filed Mar. 17, 1967, now U.S. Pat. No. 3,551,411. This invention relates to compounds of the formulae:

I Xe wherein R R R and X are as defined below:

wherein R R and R are as defined below:

R and R is, independently, either a hydrogen atom, linear alkyl having from 1 to 4 carbon atoms, or linear alkoxy having from 1 to 4 carbon atoms; alternatively, R and R are joined to form methylenedioxy 3,655,648 Patented Apr. 11, 1972 R is linear alkyl having from 1 to 4 carbon atoms; and X is a halogen, e.g. Cl, Br and I;

and pharmaceutically acceptable acid addition salts of compounds (C).

The compounds of this invention may be prepared by the following reaction scheme; R R R and X being as defined above.

Stpe (2.)

i R2 N 8 R2 $N 15, L e n o 3 RN 0 Step (b) R NR Reduction, e.g. Na in NH3 1 N/\ H Step (0) R NR Reduction, e.g. LAH R According to the reaction scheme: Step (a) is a conversion of a 2-oxo-1,2,3,5,6,lob-hexa- 5 hydroimidazo[2,1-a]isoquinolin-2-one by reaction with R X, i.e. a lower alkyl halide, e.g. CH I, to form the quaternary ammonium halide, i.e. a compound (A). 2- 0x0 l,2,3,5,6,10b hexahydroimidazo[2,1-a]isoquinolin- 2-ones may be obtained by following the procedure disclosed by D. Beke and L. Toke in Chim. Berichte, vol. 95, pp. 2122-2131, (1962).

Step (b) is a reduction of compound (A) to compound (B), effected by use of sodium in liquid ammonia resulting in the cleavage of the nitrogen-to-carbon bond common to the G-membered nitrogen-containing ring and the S-membered lactam ring, thus forming a 9-membered lactam ring containing two nitrogen atoms.

Step (c) is a reduction of compound (B); i.e. the lactam, to compound (C), effected by use of an agent suitable for the reduction of a carbonyl group, e.g. heating with lithium aluminum hydride (LAH) in a suitable solvent, e.g. diethylether (ether).

The pharmaceutically acceptable acid addition salts of compounds (C) are prepared from the corresponding free base [compounds of Formula C] according to artrecognized procedures well-known to the art-skilled. Among the pharmaceutically acceptable acid addition salts are salts of organic acids, e.g. tartaric acid; inorganic acids, e.g. hydrochloric acid, hydrobromic acid and sulfuric acid; monobasic acids, e.g. an alkanesulfonic acid, such as methanesulfonic acid (H C-SO H); dibasic acids, e.g. succinic acid; tribasic acids, e.g. phosphoric acid and citric acid; saturated acids, e.g. acetic acid; ethylenically unsaturated acids, e.g. maleic acid and fumaric acid; and aromatic acids, e.g. salicylic acid and arylsulfonic acids, such as benzenesulfonic acid. The only limitation on the acid selected is that the resulting acid addition salt is pharmaceutically acceptable; the acid does not nullify the therapeutic properties of the free base.

Compounds (C) and the pharmaceutically acceptable acid salts of compounds (C) are useful as antidepressants, analgesics and anti-infiammatories. They are administered to mammals either orally or parenterally in standard dosage forms, e.g. tablets and capsules, in daily doses of from 10 to 40 mg./kg. Although administration is preferred in equally divided doses from 2 to 4 times per diem, each of said compounds may also be administered in a single daily dose.

Each of the pharmaceutically active compounds of this invention may be, e.g., incorporated, for oral administration, in a tablet as the sole active ingredient. A typical tablet is constituted by from 1 to 3 percent binder, e.g. tragacanth; from 3 to 10 percent disintegrating agent, e.g. corn starch; from 2 to 10 percent lubricant, e.g. talcum; from 0.25 to 1.0 percent lubricant, e.g. magnesium stearate; an average dosage of active ingredient; and q.s. 100 percent of filler, e.g. lactose; all percentages being by weight. Tablets are prepared according to standard tabletting techniques, which are well-known in the art, employing the necessary amounts of conventional granulating liquids, e.g. alcohol SD-30 and purified water. An exemplary tabletting formulation for the instant active compounds is:

Parts Title compound of Example 3 85 Tragacanth 2 Lactose 4.5 Corn starch 5 Talcum 3 Magnesium stearate 0.5 Alcohol $13-30} qg, Purified water In the following examples all temperatures are in degrees centigrade. Parts and percentages are by weight unless otherwise specified. The relationship between parts by weight and parts by volume is the same as that between the kilogram and the liter.

EXAMPLE 1 8,9-dimethoxy-4-methyl-1,2,3 ,5 ,6, 1 Ob-hexahydroimidazo [Ll-a]isoquinolinium iodide This example illustrates the preparation of compounds (A). Compounds (A) may be used in the preparation of compounds (B) as is illustrated in Example 2.

A solution of 1 part of 8,9-dimethoxy-l,2,3,5,6,10bhexahydroimidazo[2,l-a]isoquinolin-2-one in 5 parts by volume of ethanol and 5 parts by volume of methyl iodide is allowed to stand for 16 hours. The resulting precipitate is collected by filtration yielding 1.1 parts of crude prod uct which is then recrystallized from water yielding 0.5 parts of the title compound.

Replacing the 8,9-dimethoxy-1,2,3,5,6-10b-hexahydroimidazo[2,1-a]isoquinolin-2-one, i.e. a compound wherein R and R are lower alkoxy with an equivalent amount of 8,9 dimethyl 1,2,3,5,6-l0b hexahydroimidazo[2,1-a] isoquinolin-Z-one, i.e. a compound wherein R and R are lower alkyl, or 8,9-methylenedioxy-1,2,3,5,6,10b-hexahydroimidazo[2,1-a]isoquinolin-Z-one, results in the preparation, in a similar manner, of the corresponding compounds (A). Likewise, use of ethyl iodide in place of the methyl iodide gives the corresponding compound (A).

CHaO

4 EXAMPLE 2 9,10-dimethoxy-S-methyl-2,5-benzodiazonin- 3-one hydrochloride rHCl 5 parts of 8,9-dimethoxy-4-methyl-l,2,3,5,6,10b-hexahydroimidazo[2,l-a]isoquinolinium iodide in parts by volume of liquid ammonia cooled in a Dry Ice-acetone both. The reaction mixture is stirred for one hour and then allowed to evaporate over a period of 16 hours. The resulting residue is dissolved in a mixture of methanol, water and ether; the ether layer is then separated and dried over sodium sulfate and then evaporated. The residue is converted to the hydrochloride salt and is crystallized from ethanol, yielding 2.2 parts of the title compound, M.P. 252 to 253 C.

Replacing the 8,9 dimethoxy-4-methyl-1,2,3,5,6,10bhexahydroimidazo[2,l a]isoquinolinium iodide, i.e. a compound (A) wherein R and R are alkoxy groups, with an equivalent of 8 methyl 9 propoxy-4-methyll,2,3,5,6,10b hexahydroimidazo[2,1 a]isoquinolinium iodide, i.e. a compound (A) wherein R is lower alkyl and R is lower alkoxy, results in the preparation of the corresponding compound (B) in similar manner.

EXAMPLE 3 9,10-dimethoxy-S-methyl-Z,5-benzodiazonine bimaleate CH;O NCH i HC-COOH omo HCCOOH This example illustrates the preparation of compounds (C).

A solution of 6 parts of compound (B) in 30 parts by volume of THF (tetrahydrofurane) is added to a solution of 3 parts of LAH in 200 parts by volume of ether and the mixture heated under reflux for 16 hours. The reaction mixture is then decomposed by the addition of water and filtered through Celite (diatomaceous earth). The organic phase is separated and evaporated under vacuum. The residue is converted to the maleate salt which is then crystallized from ethanol-ether yielding 5.4 parts of compound (C), M.P. 154 to 158 C.

Replacing the 8,9 dimethoxy-5-methyl-2,5-benzodiazonin-3-one, a compound (B) wherein R and R are lower alkoxy groups, with 8-methoxy-5-methyl-2,S-benzodiazonin-3-one, a compound (B) wherein R is lower alkoxy and R is a hydrogen atom, results in the preparation, in a similar manner, of the corresponding compound (C).

It is thought that the invention and its advantages will be understood from the foregoing description. It is apparent that various changes may be made in the structures of the compounds without departing from the spirit and scope of the invention or sacrificing its material advantages. The examples merely provide illustrative embodiments.

What is claimed is: 1. A compound of the formula:

wherein each of R and R is, independently, either a References Cited hydrogen atom, linear alkyl having from 1 t0 4 UNITED STATES PATENTS carbon atoms, or linear alkoxy having from 1 to 4 Y carbon atoms; or R1 and R2 are joined to form 3,294,782 12/1966 sulkowskl 260239.3 B q y fif -2 2 t 5 HENRY R. JILES, PrimaryExaminer 1s mear a y rom 0 car on aoms; or a pharmaceutically acceptable acid addition salt there- BOND Asslstant Exammer US. Cl. X.R. 2. The compound according to claim 1 wherein each f 1 and 2 is methoxy and 3 is methyL 10 260239 BD, 239.3 T, 287, 286, 340.5; 424 -244 

